The method of using an anisotropic conductive film for electrical connection between substrates is well known. Japanese Patent Application Laid-Open No. 4-317347 describes the bonding of a semiconductor chip and substrate in which this method is applied to flip-chip bonding.
A resin-based adhesive such as an anisotropic conductive film has high adhesion with the substrate, and therefore the adhesive itself has poor flowability, as a result of which holes and voids tend to form in and around the position of mounting an IC. Holes and voids act as gathering places for moisture, and thus have an adverse effect on reliability.
The present invention solves this problem, and has as its objective the provision of a semiconductor device and method of manufacture thereof, a circuit board, and an electronic instrument, such that holes and voids do not occur in and around the position of mounting an IC.